Over the last few weeks, Senator John McCain has been seen wearing a walking boot for, what he claims, is part of his treatment for an "Achilles injury," yet the boot has mysteriously switched feet.

The Achilles heel, also known as the calcaneal tendon, is the largest tendon in the body and runs down the back of the leg to the heel bone.

Injuring the Achilles is common among athletes and such an injury can be extremely painful, taking weeks or months to heel, usually leaving a person unable to walk through the recovery process.

Aside from the fact that a right-fitting boot wouldn't fit on a left foot, taking a supportive walking boot off and wearing on the other foot would cause excruciating pain for the sufferer, and most likely severely impede the healing process.

This bizarre foot swapping of McCain's boot adds to suspicions that the injury is actually fake and the boot is being used to cover something, possibly an ankle monitor.

People will be quick to assume that these images have been edited and reversed to make it look as though the foot has been switched, but they are from Senator McCain's official Twitter account, and details in the images prove they haven't been altered.

"Senator McCain was treated at Walter Reed Medical Center over the weekend for a minor tear in his right Achilles tendon, as well as for other normal and non-life-threatening side effects of cancer therapy. Senator McCain has returned to work in the Senate and will be wearing a walking boot until his injured tendon is fully healed."

McCain also tweeted a photo of himself that day, with the caption, "I can't tell you how much I hate wearing this boot!"

McCain can be seen wearing a controlled ankle motion medical boot on his right leg.

In a subsequent Tweet on November 14, McCain is wearing the boot, still on his right leg.

However, when Senator McCain posted a picture of himself and his wife on November 22, the boot had strangely switched to his left leg.

A plausible explanation for the anomaly is that the photo could have been "inverted" or "reversed," however, an analysis of other elements of the scene that would also have appeared to change sides, such as the buttons on McCain's jacket, or the hand upon which his wife's wedding ring sits, dispels that idea.

Social media users have offered up a variety of theories as to what may be the reason for the aberration, ranging from McCain quickly recovering from his original injury and then somehow wounding his opposite leg, to the injury having been faked to garner sympathy, to his own confusion as a result of his brain tumor, to the idea that McCain may be concealing an ankle monitor.

Senator McCain, who is 81-years-old, was diagnosed with an aggressive form of brain cancer in July, raising questions about his physical and mental fitness to serve in public office.

The theory that John McCain is wearing a medical boot to hide his ankle monitor as a criminal defendant just got legs.